Here are seven things to watch — other than the presidential race — as the results pour in on Tuesday night.

Will Alabama GOP voters welcome back Jeff Sessions?

The former attorney general is probably the best bet among the top three Republican candidates to snag a spot in the all-but-certain runoff that occurs if no candidate receives 50 percent of the vote in Tuesday’s primary. He’s facing former Auburn University football Coach Tommy Tuberville and Rep. Bradley Byrne, along with several other low-polling candidates. The top three contenders have all run campaigns leaning heavily on their credentials as the most pro-Trump Republican in the race, a complicated argument for Sessions, whom Trump drummed out of his cabinet.

Sessions’ frosty relationship with the president is well-known, though he still has a positive image among GOP primary voters. Sessions has run ads reminding voters he was the first senator to endorse Trump in 2016, but his rivals have accused him of abandoning Trump during his time running the Justice Department, particularly with a late flurry of negative ads as the race closed. Byrne is running on his House record supporting Trump, and Tuberville as a non-politician outsider.

No candidate’s spot in the runoff is assured, and Tuesday’s results could give key insight into what sort of test Sessions could face in growing his support over the next four weeks ahead of the March 31 runoff for the nomination to take on Democratic Sen. Doug Jones.

Democrats fight to get their guy in North Carolina

North Carolina could be the decisive Senate seat in the battle for the majority. And after an eventful final month that included a significant meddling effort from Republicans, Democrats seem poised to get their preferred candidate to take on GOP Sen. Thom Tillis.

Cal Cunningham, a veteran and former state senator who has broad backing both in Washington and North Carolina, has opened up a wide lead over state Sen. Erica Smith in recent polls after a flurry of spending in the race. An NBC News/Marist poll released Sunday showed Cunningham ahead of Smith by 33 points.

A super PAC funded by allies to Senate Majority Leader Mitch McConnell waded into the primary, spending more than $2.9 million to boost Smith, dwarfing her own campaign resources even as she disavowed the intervention.

Cunningham and outside allies eclipsed that spending significantly: His campaign spent seven figures on TV and ran coordinated ads with the Democratic Senatorial Campaign Committee, while outside groups spent more than $11 million on the airwaves, all running mostly positive ads boosting his message and name identification in the state.

Tillis faces only nominal opposition after his self-funding primary challenger flamed out last year. The first-term GOP senator is running as a reliable Trump ally and getting a major boost from the president, who is holding a pre-Super Tuesday rally in Charlotte on Monday night.

Texas Democrats look for the next Beto

There are a dozen Democrats on the ballot for Senate in Texas on Tuesday, but the national party has made its choice: DSCC-endorsed MJ Hegar is the favorite to finish first, but well short of the majority of the vote she would need to win the nomination outright.

After Hegar, it’s a muddle. In an NBC News/Marist poll released Sunday, Hegar had 16 percent support from likely primary voters. Cristina Tzinztún Ramirez, an activist, had 9 percent and state Sen. Royce West had 8 percent. Several other candidates, including Houston City Council member Amanda Edwards and former Rep. Chris Bell, were not far behind, and one-third of voters had yet to make up their minds.

Two years after then-Rep. Beto O’Rourke raised $80 million and put a massive scare into GOP Sen. Ted Cruz, Democrats are hoping to do it again in 2020. But challenging Sen. John Cornyn in a presidential year will be more difficult. While two Democrats will likely have to fight it out through a late-May runoff, Cornyn, who faces no credible primary challenger, is sitting on a $12 million war chest.

The incumbents who could lose

Super Tuesday could bring the ouster of the first House incumbent of the 2020 cycle. Three members — two Democrats and one Republican — have a real shot of being denied their party’s nomination.

In South Texas, Democratic Rep. Henry Cuellar is facing a fierce challenge from Jessica Cisneros, a 26-year-old immigration attorney who has become a cause célèbre on the left and boasts endorsements from Sen. Bernie Sanders (I-Vt.) and Rep. Alexandria Ocasio-Cortez (D-N.Y.). A national network of progressive donors have given her solid funding, but Cuellar — one of the most conservative members of the Democratic conference — insists that her support for "Medicare for All" and the "Green New Deal" don’t play well in the district.

Meanwhile, in California’s Central Valley, Blue Dog Democratic Rep. Jim Costa is facing a liberal opponent in Fresno City Councilwoman Esmeralda Soria. Only one of them is likely to advance from the top-two primary with a Republican, but Costa is the favorite after outspending her by more than 4-1.

In north Texas, Rep. Kay Granger, one of just 11 Republican women left in the House, is facing a stiff challenge from technology executive Chris Putnam. Backed by the conservative Club for Growth, he’s hitting Granger as a big-spending appropriator who is running up the deficit. But Granger has establishment backing and the all-important Twitter endorsement from President Trump. This race could be a test of whether small-government attacks still animate Republican voters in the Trump era.

Can a Bush win in a GOP primary in the Trump era?

The GOP primary in Texas’s 22nd congressional district in the southern suburbs of Houston offers a unique political science experiment. Pierce Bush, the grandson of George H.W. Bush and nephew of George W. Bush, is testing the appetite for compassionate conservatism in Trump’s GOP.

Party recruiters feel Bush, a nonprofit leader, would be a top-tier general election candidate in a district that has become an emerging battleground in recent years, in part because of his family name and his unique connection to the many minority communities in the district. But first he has to get through a 15-candidate primary — in which his top opponents are questioning his loyalty to Trump.

Elsewhere in Texas, a slew of Democrats, including 2014 gubernatorial nominee Wendy Davis, are vying to win the nominations in a half dozen GOP-held seats that came close to flipping in the midterms. Republicans will nominate challengers to freshman Democratic Reps. Lizzie Fletcher and Colin Allred. Expect many of these races to head toward a May 26 runoff.

The California-25 special election

Tuesday’s special election will whittle down the list of contenders vying for former Democratic Rep. Katie Hill’s northern Los Angeles district. House Democrats feel confident their preferred candidate, state Assemblywoman Christy Smith, will advance to a runoff on May 12 and have been spending to try to pick her opponent.

Private polling from both parties indicates a two-way race for the second spot between Navy veteran Mike Garcia and former Rep. Steve Knight, who lost to Hill by 8 points in 2018. The DCCC hopes to face Knight, who has had abysmal fundraising and is likely wounded after a bruising midterm, so they have dropped nearly $500,000 in ads to kneecap Garcia. Liberal radio host Cenk Uygur is running, as is former Trump adviser George Papadopoulos — but neither is expected either to advance.

The former members making a comeback

Two former Republican congressmen drummed out during the 2018 midterms, Pete Sessions and Darrell Issa, are attempting 2020 comeback bids. But in a sign of just how quickly the suburbs have trended away from the GOP, they have both decided to run in new districts.

Issa, who retired last year from a seat Democrats ultimately flipped by 13 points, is vying for a top-two finish in the race for a district vacated by embattled GOP Rep. Duncan Hunter. Radio host Carl DeMaio and 2018 Democratic nominee Ammar Campa-Najjar are Issa’s main competition.

Even though the 50th is California’s most Trump-friendly district, Campa-Najjar is likely to finish in the top two, with Issa and DeMaio competing for GOP votes.

Over in Texas, Sessions moved 100 miles south from the suburban Dallas district he handily lost in 2018 to run for a deep-red, open seat based in Waco. That district’s incumbent, retiring Republican Rep. Bill Flores, has spurned a run by his former colleague. Sessions has a shot at earning a runoff berth. He’s been slow to fundraise this cycle but had $380,000 leftover in the bank from the 2018 midterms to apply to his campaign this year.